Shock absorber



Allg. 15, 1933. R H. MOULTQN 1,923,011

SHOCK. ABSORBER Filed July 5, 1928 Patented Aug. 15, 1933 UNITED STATES PATENT OFFICE 28 Claims.

This invention pertains to shock absorbers or cushioning devices, and more particularly to that class of device adapted to be used on road vehicles, airplanes, track vehicles, or in fact, be-

tween any parts having relative movement therebetween where it is desired to retard or cushion the movements between said parts.

In shock absorbers now in use, there are a great many of the Yso-called hydraulic type. Some of the finer of this type are double acting, but at the expense of added weight and ner fitted parts, to prevent leakage and insure practical operation. This type of shock absorber is necessarily quite expensive, and in l5 fact, the expense is such as to be almost prohibitive for cars of the cheaper type. There are other well-known types of hydraulic shock absorbers which do not involve the snubbing action, or employ only the snubbing action. In other words, they are not double acting,v and even withsuch devices, the cost is not within the price range of mechanical snubbers, though it is admitted the hydraulic shock absorbers are decidedly advantageous and desirable. Further, even the most expensive shock absorbers to not provide means for increasing the snubbing action, which is desirable, especially in heavy duty work. 'Ihat is, the movement in either direction is balanced, which is often times not desirable and does not meet particular needs. It lis therefore an object of the invention to provide a cushioning device utilizing a fluid as an absorber medium.

Another object is to provide a device for effectively cushioning shocks between parts from a plurality of directions.

Yet another object is to provide a double acting checking or cushioning device using a plurality of checks in each direction of operation,`

and one which combines the action of a shock absorber and a snubber.

A further object is to provide a cushioning device wherein it is possible to vary the resistance to operation in either direction.

A still further object is to provide a cushioning device readily adaptable to all uses, as on road vehicles, railroad draft gear, between parts of track vehicles having relative movement, airplanes, engine or other prime or secondary mov- 500 ers and their beds, in fact, between any parts having relative movement, to cushion or check said parts in operation thereof.

Yet further objects are to provide a fluid cushioning device of lighter and sturdier structure than those used, one in which little Wear takes place, one that is easy tov manufacture and requires little or no attention once installed, one which more adequately meets service conditions, and one which is inexpensive to make and maintain and fuliills all requirements 6o of service and manufacture.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out e5 in `the specification, drawing and claims appended hereto.

In the drawing, which 'illustrates an embodi-4 ment of the device and wherein like reference characters are used to designate like parts- Figure 1 is a sectional elevation of the cushioning device embodying the invention;

Figure 2 is a sectional top plan View through the piston and associated parts of the device illustrated in Figure 1, the same being taken substantially in the plane as indicated by the line 2-2 of Figure l;

Figure 3 is a fragmentary sectional elevation of a modified form of cushioning device.

Referring rst of all more particularly to the device illustrated in Figures 1 and 2, said device consists essentially of a Acylinder 10 threaded as at 11, for the reception of the cap 12, said cap being provided with lubricating means 13, which may take the form of a removable screw, and said cap is also provided with an upstanding threaded screw 14, adapted to form securing means with a bracket 15, said means including rubber cushioning members 16, disposed on either side of i a portion of the bracket 15 and retained by a nut to form a rubberized substantially universal joint, it being understood that the bracket 15k may be secured to the body of a vehicle, or to any moving part.

A piston 18 is provided inthe cylinder, said piston in its normal position being substantially centered as shown, and said piston may consist of an upper retaining plate 19, screwthreaded as at 20 to the piston rod 21. Between the retaining plate 19 and a spacing ring 22, a piston leather 23 is provided, having anfupwardly extending annular or flange portion having sliding engagement with the cylinder 10, and between this spacing ring and a bottom plate 24 there is provided a similar leather 25, having a dbwnwardly extending annular portion having sliding engagement with the cylinder walls, said assemblage being provided with an adjusting nut 26 threaded to the piston rod 21, for maintaining the parts of the assemblage in proper operative position with respect to each other.

The assemblage shown is provided with a channel or recess 27 in the piston head, the same communicating through apertures 28 with the channel 29 in the hollow piston rod 21, and the spacing ring 22 is also provided with channels or apertures 30 leading to the walls of the cylinder and having portions 31 communicating with the leather 23 and 25. The piston rod 21 passes through a gland or stuffing box 32 in the base of the cylinder, the same being of any construction, such as the nut 33, which may be welded, as at 34, (or screw threaded) to the bottom of the cylinder, said nut having threaded engagement with an adjustable nut 35, between which nuts the packing 36 may be disposed. The channel 29 adjacent the lower portion of the piston rod may be vented to the atmosphere by means of apertures 37 and 38, and said piston rod is preferably threaded as at 39, adapted to be secured to the bracket 40 by means of upper and lower nuts 41 and 42, and rubber insulation 43 providing a rubberized substantially universal joint. The bracket 40 then may be secured to any means 41 for attachment to the axle or a part relatively movable with respect to the part to which the bracket 15 is secured.

So fary it will be appreciated that the construction is very similar to application Serial No. 237,355, filed December 3, 1927, to whichthis application may be referred for common subject matter,

Means may be provided for increasing the resistance to movement of the piston in one direction of travel, say, for instance,- the rebound or snubbing direction, which means may consist of a Valve member 44 consisting essentially of a housing 45, carried by the cap 12 and communicating withthe upper portion of the cylinder above the piston, the housing being provided with a valve member 46, spring controlled by means of the plunger 47, in engagement therewith, and a spring 48, adjusting means 49 being provided for imparting adjustment to the spring 48, a cap 50 serving to complete the assembly to prevent any misadjustment or interference with the parts. A conduit 51 is secured to the housing 45 and communicates with said'housing above the valve 46, a suitable connection 52 maintaining the housing and conduit in operable relation. The conduit extends downwardly and is secured by a suitable joint 53 to a fitting 54 communicating with the bottom of the cylinder on the under side of the piston. A check valve 55 is provided in the base of the cylinder communicating with the under side of the piston, said valve consisting essentially of a housing 55, communicating with the atmosphere as at 57, and with the bottom of the cylinder as at 58, the valve 59 being spring pressed by the plunger 60 and the spring 61 into engagement with the valve seat, suitable adjusting means and a cap 62 and 63 respectively being provided.

It will be appreciated that the spring 48, mounted over the valve 46 is adjusted in such a manner that the valve will not open until a predetermined pressure is developed on the upper side of the piston. Normally this valve is held closed by the yspring above it and opens in the same manner and under the same conditions that obtain in the above referred t application. In a similar manner, the spring 61 of the valve 55 is adjusted so that proper bleeding action takes place.

In the operation of this device let it be assumed that the piston is moved upwardly with respect to the cylinder. The air above the piston will be compressed until such time as it overcomes the tension in the spring 48, at which time the valve 46 will be opened, and instead of the exhausted air passing to the atmosphere, it will now pass through the conduit 51 to the under side of the piston, for increasing the pressure of the air therein. Upon the initial movement of the piston upwardly, and before the air pressure has opened the valve 46, the pressure of the air below the piston is decreased, tending to form a vacuum. However, this is broken by airbeing drawn through the ports 37 and 38, through the channel 29, through apertures 28, into the space 27, and through channel 22, past the lower leather 25, and into the lower portion of the cylinder. When, however, such pressure has been built up in the upper portion of the cylinder to open the valve 46, as before explained, air will pass through the conduit 51 to the under side of the piston. However, air is not drawn in through the hollow piston rod and then to the under side of the piston, as the compressed air is forced into the cylinder under the piston, for obviously the compressed air has the eifect of sealing the lower leather against the side of the cylinder, so it will be seen that with the pressure of the air on the under side of the piston thus built up to a point above atmospheric pressure (and this can be made of any practical value) that the pistonI 14 in its downward movement will haveI no free rebound, as such is immediately resisted in its downward movement by the compressed air trapped in the lower portion of the piston, which can not return through the valve 46, as it is a one way valve. The piston, however, in going down or returning, forces the compressed air out through the bleed valve 55. Therefore, it will be readily understood that in this form of the device, compressed air is supplied only to the lower portion of the cylinder, and so with regard to pressures, this device in this sense is not double acting. It is, however, double acting in regard to the `ordinary shock absorbing and snubbing actions as described in the above identied application. It will be readily appreciated that if the valve mechanism and conduit be reversed that the action is reversed, that is, the shock absorbing motion is arrested by initial compressed air, rather than the snubbing as described.

However, referring more particularly to Figure 3, which is for heavy duty work, such as airplanes or track vehicles, it may be advantageous to have the device double acting with respect to the compressed air feature, in which case a valve 144, similar to the valve assembly 44 is provided in the bottom of the cylinder, and communicates through conduit 151 to the upper portion of the cylinder, so that this assembly is similar in action only in a reversed direction to the valve assembly 44. In this case, then, a check valve 155 is provided in the top, similar toe the check valve 55 provided in the bottom, only operable in a reverse direction, it being understood that the valves 144 and 44 operate con- `ment therein, a piston rod associated with said piston, means insaid piston for causing ow of fluid into said cylinder from outside of said cylinder upon movement of said piston, and means extending from both ends of said cylinder for conducting fluid from onel end of said cylinder to the other whereby fluid is conducted from one side of said piston to the other.

2. In a cushioning device, the combination of a cylinder, a piston relatively movable therein, means for causing flow of fluid into said cylinder from the atmosphere upon movement of saidl piston in either direction, and means extending on each side of said piston for exhausting fluid from one side of said cylinder to the other in one direction only.

3. In a cushioning device, the combination of a cylinder, a piston relatively movable therein and means .for causing supply of fluid to one side of saidpiston, whereby excess pressure is built up on said side of said piston.

4.'In a cushioning device, the combination of a cylinder, a piston relatively movable therein, means permitting supply of uid to one side of said piston and means for causing supply of fluid to one side of said piston, whereby excess pressure is built up on said side of said piston. 5. In a cushioning device, the combination of a cylinder, a piston relatively movable therein, means permitting supply of fluid to one side of lsaid piston and additional means for causing supply of fluid to the same side of said piston whereby excess pressure is built up on said side of said piston.

6. In a cushioning device, the, combination of a cylinder, a piston relatively movable therein, means permitting iiuid suppy to one side of said piston upon movement in one direction and before reversal of the direction` this movement thereof, means for supplying uid to one side of said piston to increase fluid pressure thereunder to above the initial pressure, .and means causing bleeding of fluid from one side of said piston.

7. In a cushioning device, the combination of a cylinder, a piston relatively movable therein,I means permitting iluid lsupply -tor one side of said piston upon movement thereof, means for supplying fluid to one side of said piston to increase fluid pressure thereunder, and means causing bleeding `of fluid outwardly of said device from the side of said piston whereunder the excess pressure has been built.'

8. In a `cushioning device, the combination of a cylinder, a piston relatively movable therein, means permitting supply of uid to one'side of said piston and additional means for causing supply of fluid to one side of said piston whereby excess pressure is built up on said side of said piston and for rendering said first named means inoperative, and means for exhausting compressed fluid externally of said cylinder.

9'. Ina cushioning device, the combination of a cylinder, a piston relatively movable therein, means permitting supply of fluid from said piston to one side of said piston and means for causing supply of fluid to the same side of said piston whereby excess pressure is built up on said piston and for rendering said first named means inoperative and means for permiting bleeding iluid from one side of said piston.

10. Inra cushioning device, the combination of a cylinder, a piston relatively movable therein, a piston rod associated with said piston, means for causing fluid supply to said cylinder from :aid piston when said piston is moved, a bypass from one side of said piston to the other, and means in said bypass permitting flow of fluid from one side of said piston to the other whereby excess pressure is built up on said side of said piston.

1l.` In a cushioning device, thecombination of a cylinder, a pistonA relatively movable therein, a piston rod associated with said piston, means Vin said piston and piston rod for causing uid supply to either side of said cyinder from which the piston is travelling, ,directly from said piston when said piston is moved, and bypass means for conducting fluid in said cylinder from one side of said piston to the other.

12. In a cushioning device, the combination of a cylinder, a normally centered piston movably mounted therein, a piston rod associated with said piston, said piston rod and piston having means therein causing fluid supply to the part of said cylinder from which said piston is moving, means for conducting fluid from the side of said cylinder toward which said pisto-n is moving to another part of said device, and normally finoperative exhaust means in said cylinder on one4 side of said piston.

13. In a shock absorbing device, the combination of a cylinder, a piston movably disposed in said' cylinder, a piston rod xedly secured to said piston, said cylinder and said rod having means thereon for attachment to relatively movable parts, means for causing flow of air fromv the atmosphere to either end of the cylinder from which the piston is traveling upon movement of said piston and means on said cylinder extending on each side of said piston for exhausting air from one side of said cylinder to the other in one direction only.

14. In a shock absorbing device, the combination of a cylinder, a piston movably disposed in said cylinder, a piston rod xedly secured to said piston ,and extending outwardly of said cylinder, said cylinder and rod having means thereon for attachment to relatively movable parts, said piston and rod having communicating meanstherein, the means in said rod being in communication with the atmosphere, means on said piston acting to admit air from the atmosphere from said piston to the portion of the cylinder from which the piston is travelling and a by-pass connection extending from one side of said piston to the other for supplying air in excess of atmospheric pressure from the end of said cylinder. towards which the piston is travelling to the end of said cylinder from which the piston is travelling. Y

15. In a shock absorbing' device, the combination of a cylinder, a piston movably disposed in said cylinder, a. piston rod ixedly secured to said iston and extending outwardly of said cylinder, said cylinder and red having means thereon for attachment to relatively movable parts, said piston and rod having communicating means therein, the meansin said rod being in communication with the atmosphere, means on said piston acting to admit air from the atmosphere from said piston tothe portion of the cylinder from which the piston is travelling and a by-pass connection extending from one side of said piston to the other for supplying air in excess of atmospheric pressure from the end of said cylinder towards which the piston is travelling to the end of said cylinder from which the piston` is travelling, and means for supplying air from the atmosphere to one side of said cylinder.

16. In a shock absorbing device, the combination of a cylinder, a piston movably disposed in said cylinder, a piston rod xedly secured to said piston and extending outwardly of said cylinder, said cylinder and rod having means thereon for attachment to relatively movable parts, Said piston and rod having communicating means therein, the means in said rod being in communication with the atmosphere, means on said piston acting to admit air from the atmosphere from said piston to the portion of the cylinder from which the piston is travelling and a by-pass connection extending from one side of said piston to the other for supplying air in excess of atmospheric pressure from the end of said cylinder towards which the piston is travelling to the end of said cylinder from which the piston is travelling, and means for supplying air from the atmosphere to one side of said cylinder, after said piston has travelled a predetermined amount from that portoin of the cylinder from which the piston has travelled.

17. In a shock absorbing the combination of a cylinder, a piston movably disposed in said cylinder, a piston rod xedly secured to said piston andextending outwardly of said cylinder, said cylinder and rod having means thereon for attachment to relatively movable parts, said piston and rod having communicating means therein, the means in said rod being in communication with the atmosphere, means on said piston acting to admit air from the atmosphere from said piston to the portion of the cylinder from which the piston is travelling and a by-pass connection extending from one side of said piston to the other in all positions of said piston and operative subsequently to the air supply through said means on said piston for supplying air in excess of atmospheric pressure from the end of said cylinder towards which the piston is travelling to the end of said cylinder from which the piston is travelling.

18. In a shock absorbing device the combination of a cylinder, a piston movably disposed in said cylinder, a piston rod xedly secured to said piston and extending outwardly of said cylinder, said cylinder and rod having means thereon for attachment to relatively movable parts, said piston and rod having communicaing means therein, the means in said rod being in communication with the atmosphere, leathers on said piston acting to admit air from the atmosphere from said piston to the portion of the cylinder from which the piston is travelling, and a by-pass connection in said cylinder extending from one side of said piston to the other in all positions of said piston and means for supplying air from the atmosphere to one side of said cylinder after said piston has travelled a predetermined amount from that end of the cylinder from which the piston has travelled.

19. In a shock absorbing device the combination of a cylinder, a piston movably disposed in said cylinder, a piston rod iixedly secured to said piston and extending outwardly of said cylinder, said cylinder and rod having means thereon for attachment to relatively movable parts, said piston and rod having communicating means therein, the means in said rod being in communication with the atmosphere, leathers on said piston acting to admit air from the atmosphere from said piston to the portion of the cylinder from which the piston is travelling and a by-pass connection in said cylinder extending from one side of said piston to the other in all positions of said piston and op erative subsequently to the air supply through said leathers and means for supplying air from the atmosphere to one side of said cylinder after said piston has travelled a predetermined amount from thatY end of the cylinder from which the piston has travelled.

20. In a checking device wherein the cushioning medium is air only, the combination of a cylinder, a piston movably mounted therein, a piston rod xedly secured to said piston for movement therewith, means on said piston for permitting supply of' air from a source external of said cylinder to the portion of said cylinder from which said piston is moving, and means on said cylinder for permitting supply of air to a portion of said cylinder, one of said means remaining substantially inoperative until a vacuum is substantially set up in the portion of said cylinder from which said piston is traveling.

2l. In a pneumatic cushioning device wherein the cushioning medium is air only, the combination of a casing, apiston movably mounted in said casing, a piston rod xedly secured to said piston and extending outwardly of said casing, said piston rod and casing having means thereon for securing said device to relatively movable parts, means for supplyingair to said cylinder from a source external of said cylinder upon movement of said piston, and means on said cylinder for supplying air from one side of said piston to the other, one of said means remaining inoperative until a vacuum is substantially set up in a portion of said cylinder.

22. In a pneumatic cushioning device wherein the cushioning medium is air only, the combination of a casing, a piston movably mounted in said casing, a piston rod xedly secured to said piston and extending outwardly of said casing, said piston rod and casing having means thereon for securing said device to relativelyy movable parts, means for supplying air to said cylinder from the atmosphere upon movement of said piston, and means on said cylinder for supplying air from one side of said piston to the other, one of said means remaining inoperative until a vacuum is substantially set up in a portion of said cylinder from which said piston is traveling.

23. A shock absorber including in combination, a cylinder, a piston mounted in said cylinder, means for attaching the absorber to relatively movable parts of a vehicle, and relief venting means in said cylinder on each side of the piston, one of said venting means communicating with the opposite end of said cylinder, said piston having channel means therein, said channel means and one of said venting means opening to the atmosphere.

24. A shock absorber including in combination, a cylinder, a piston movably mounted in said cylinder and means whereby thel cylinder and piston are attached to relatively movable parts of an automobile or other` vehicle, the said piston having an air chamber in the head thereof normally connecting said air chamber outwardly of said cylinder, whereby the end of the cylinder from which the piston is moving is connected outwardly of said cylinder, but closed to the end of the cylinder toward which the piston head is moving, and means connecting said ends of said cylinder.

25. .ln a cushioning device, the combination of a casing, a movable member mounted therein to normally separate said casing into 'a plurality of chambers, means for conducting fluid to one of said chambers from the chamber into which the movable member is'advancing upon movement thereof, means for conducting iiuid out- Uwardly of the first named chamber upon reversal of movement of said movable member after a predetermined movement thereof, and means on said movable member for supplying iiuid to said chambers upon a predetermined movement of said movable member.

26. In a cushioning device, the combination of /a casing, a movable member mounted therein to normally separate said casing into a plurality of chambers, means on said casing for conducting uid to one of said chambers from the chamber into which the movable member is advancing upon movement thereof, means for conducting fluid outwardly of the rst named chamber upon reversal of movement of said movable member after a predetermined movement thereof, and means foi-supplying fluid to said chambers upon a predetermined movement of said movable member. v

27. In a cushioning device, the combination of a casing, a movable member mounted therein to normally separate said casing into a plurality of chambers, means on said casing for conducting iiuid to one of said chambers from the chamber into which the movable member is advancing upon movement thereof, means for conducting fluid outwardly of the first named chamber upon reversal of movement of said movable member after a predetermined movement thereof, and means on said movable member for supplying fluid to said chambers upon a predetermined movement of said movable member.

28. In a pneumatic cushioning device wherein the cushioning medium is air only, the combination of a casing, a piston movably mounted in said casing, a piston rod fxedly secured to said piston and extending outwardly of said casing, said piston rod and casing having means thereon for securing said device to relatively movable parts, means on the piston for supplying air to said cylinder from the atmosphere upon movement of said piston, and means on said cylinder for supplying air from one side of said piston to the other, one of said means remaining inoperative until a vacuum is substantially set up in a portion of said cylinder from which said piston is traveling.

ROLLIN H. MOULTON.

soA 

